Future of computing has Schrödinger’s cat inside

Nobel-winning take on quantum mechanics makes spooky action a bit less spooky.

Editor's note: This article originally appeared on Reuters Opinion under the title "A Nobel that points us toward our quantum future." It was republished with permission.

Scientists like to think that the true measure of our understanding is our ability to predict something, and, in experimental physics, control something. This year's Nobel prize in physics has been awarded to Serge Haroche and David Wineland for controlling the quantum world in ways that, not so long ago, were simply unthinkable. When I say, “controlling the quantum world,” I mean controlling not just the physical motion of a single atom, but also the internal state of the atom. It is the difference between being able to set off an avalanche, and control where every snowflake goes once the avalanche is in motion.

This level of precise control allows us to use the internal states of atoms, ions, and photons as information carriers, similar to bits in today’s computers. That means that certain calculations that have been impossible until now can become a lot easier. Soon, thanks to quantum computing, we’re going to be inventing things we never thought to invent before.

Ultimately, quantum research is about the pursuit of control—a pursuit that has a long history. Technology, after all, is at its most base form an attempt to better understand and manipulate nature. The first steam engines, for example, were the products of inspired engineering, based on very little understanding of heat, energy, pressure, and temperature. The desire to produce more powerful steam engines with higher efficiencies drove us to research, develop, and understand more about this aspect of nature. With that understanding came control, in this case over the thermal behavior of groups of atoms, and molecules.

The next revolution, and one that is already upon us, is driven by absolute control of individual electrons, atoms, light particles, and ions. This year's Nobel prize recognizes the latest achievement in humanity’s attempts to control and predict the natural world. I’ll eschew a deep dive into scientific detail—you can read that kind of thing here—but to understand what Haroche and Wineland have done, picture a swing. Swings have a certain rhythm to them that make them very predictable. But the quantum swings that Haroche and Wineland play with are very delicate, and the slightest passing breeze will disturb them. In short, these swings are, left to their own devices, unpredictable and short lived. That is, a quantum swing, once set in motion, quickly stops again.

Haroche and Wineland have worked on ways to keep their quantum swings in motion. Indeed, not just in motion, but predictable for long periods of time.

The commonality between Haroche and Wineland's work is control of this internal quantum swing. Talking about the future is always a dangerous business, but in this case scientists are quite clear about where all this is going: quantum information technology. The quantum laws that govern the behavior of light and matter can be harnessed to provide new technologies. The earliest applications are already on the market: you can ensure your data's security using quantum key distribution, where the laws of quantum mechanics are used to create codes to securely encrypt data.

But that pales in comparison to what’s coming: quantum computers. Quantum computers will shine in ways that are not obvious. Consider this: the strength of the fibers that make up your cotton-polyester blend jacket are determined by the quantum mechanics governing the atoms and molecules that make them up. But predicting and controlling the strength of a fabric is pretty much impossible at the moment. Essentially, the materials that we have right now are a combination of lots of lab-work, inspired insight, and blind luck. A quantum computer will change all of that.

The lack of predictability isn’t due to the failings of quantum mechanics, it's down to our failure to solve the mathematics used to describe quantum behavior. We don’t have the tools to do so. The most powerful computers in the world have difficulty computing the properties of the simplest of molecules. Quantum computers will potentially change that.

Imagine a world where a chemist can use a computer to design molecules that have particular properties. Need a strong plastic that biodegrades into harmless biproducts? Let me fire up my Q2000 quantum computer and see what we can invent. Or imagine stumbling across a new protein whose properties seem inexplicable. Again, a quantum computer will, at the very least, provide you with the beginnings of an explanation.

This is the shining promise of a future with quantum computers. It is a future that is being brought about by the great experimental physicists of our time, but, it is also a future that will be owned by biologists and chemists.

Being a scientist, I love the idea of knowing more about proteins and materials. But I think everyone else will love it too. Harder materials will increase the longevity of gadgets: who hasn’t watched in horror as the glass in their cellphone cracks after being dropped? Paints will hold their color for longer, and be more scratch resistant. Products will come in packaging that protect their contents better, but also are more environmentally friendly.

At the moment, science is limited by what it can and can’t control. If scientists can’t control something, they can’t conjure it. Quantum computers have the potential to unleash scientists, leaving them limited only by the laws of nature and their own imaginations. There's still a long way to go, but we're already taking tiny quantum baby steps.

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Chris Lee
Chris writes for Ars Technica's science section. A physicist by day and science writer by night, he specializes in quantum physics and optics. He is delocalised, living and working in Eindhoven and Enschede, the Netherlands. Emailchris.lee@arstechnica.com//Twitter@exMamaku

When we (humans) started exploring organic chemistry there were unanticipated negative consequences. As described in the article, will the same be true for quantum computing?

Watching "Deadliest Catch" and seeing us (humans) selectively eliminiating all the large crabs and letting the smaller crabs survive to reproduce, would suggest we are incapable of learning from our errors of the past. Will our hubris get us into trouble with quantum computing and the associated advancements?

When ever I read something about quantum computing they all say how they will change the world of computing but none of them explain how? Or why? This article is like politician speech promises promises promises with very little implementation details. Quantum computer guy: quantum computing will end world hunger and bring world peaceAnother guy: how?Quantum computer guy: I don't know just turn it on I guess.

Quantum computing is not yet a reality. I will believe it when I see it. It's kind of like the parallel computing myth that so many believe it, but hasn't yet come to fruition. I know this article is not about AI, but it's another myth that is popular as well. True artificial intelligence will require a computer that can write new software for itself on the fly. Anything less is nothing more than a computer with clever algorithms. I've been watching these computer fantasizers at work now for a couple of decades, and the myth-spinning just never stops. Reminds me of the much-ballyhooed "thin client" promoted by Larry Ellison of Oracle. He predicted back in the 90's, I believe, that within some number of years that PC's would all be replaced by thin clients running from central servers. Well, where are they? I'm attending college for a computer science degree, and while I see quite a few small devices being used by individuals, our classrooms are filled with supposedly extinct and useless PCs! My point is that I am not impressed by articles such as this that predict the myth of imminent "computer heaven" if only we have "the next big thing" which "will revolutionize the world". I'm tired of hearing it.

When ever I read something about quantum computing they all say how they will change the world of computing but none of them explain how? Or why? This article is like politician speech promises promises promises with very little implementation details. Quantum computer guy: quantum computing will end world hunger and bring world peaceAnother guy: how?Quantum computer guy: I don't know just turn it on I guess.

Well, at least this article was a bit more specific:

article wrote:

Let me fire up my Q2000 quantum computer and see what we can invent.

</dry sarcasm of agreement>

I think there were some hints about how it might work, but more detail would certainly be relished.

article wrote:

The lack of predictability isn’t due to the failings of quantum mechanics, it's down to our failure to solve the mathematics used to describe quantum behavior. We don’t have the tools to do so. The most powerful computers in the world have difficulty computing the properties of the simplest of molecules. Quantum computers will potentially change that.

I think the implication is that a quantum computer will be able to model a quantum system in an analog sort-of way, and that will help us to solve quantum mechanical math problems.

BTW - Q2000 doesn't sound so futuristic anymore. (maybe Q3000? Or even the less ambitious Q2100.)

Watching "Deadliest Catch" and seeing us (humans) selectively eliminiating all the large crabs and letting the smaller crabs survive to reproduce, would suggest we are incapable of learning from our errors of the past. Will our hubris get us into trouble with quantum computing and the associated advancements?

Creating random numbers is completely different from the specifics needed to make precise calculations.

I agree with some of the other comments here, wondering why most of the Quantum Computing articles over the last few years, who claim Quantum Computing to be the holy grail of computing, fail to explain, with any reasonable specifics, why it would be so much better.

Is it simply the concept of circuit density? If that's the case, CPUs are very tiny already, why can't we just build a 10x larger conventional CPU and suddenly have 10 times the processing power? I imagine the distance from one side of the chip to the other would not be nearly as great as when you have multiple CPUs in a super computer, and the material cost would be negligible.

Is it the concept of having greater than 2-bit building blocks? Would that really make it faster or just give more capacity?

Maybe this is just Quantum Physicists hypothesizing in order to get funding for the next decade.

Creating random numbers is completely different from the specifics needed to make precise calculations.

I agree with some of the other comments here, wondering why most of the Quantum Computing articles over the last few years, who claim Quantum Computing to be the holy grail of computing, fail to explain, with any reasonable specifics, why it would be so much better.

Is it simply the concept of circuit density? If that's the case, CPUs are very tiny already, why can't we just build a 10x larger conventional CPU and suddenly have 10 times the processing power? I imagine the distance from one side of the chip to the other would not be nearly as great as when you have multiple CPUs in a super computer, and the material cost would be negligible.

Is it the concept of having greater than 2-bit building blocks? Would that really make it faster or just give more capacity?

Maybe this is just Quantum Physicists hypothesizing in order to get funding for the next decade.

It's my understanding that it's because a quantum computer isn't limited to 1's and 0's like a classical computer, so there are processes that they can compute much faster.

Here's a paragraph from wiki

Quote:

Large-scale quantum computers could be able to solve certain problems much faster than any classical computer by using the best currently known algorithms, like integer factorization using Shor's algorithm or the simulation of quantum many-body systems. There exist quantum algorithms, such as Simon's algorithm, which run faster than any possible probabilistic classical algorithm.[5] Given unlimited resources, a classical computer can simulate an arbitrary quantum algorithm so quantum computation does not violate the Church–Turing thesis.[6] However, the computational basis of 500 qubits, for example, would already be too large to be represented on a classical computer because it would require 2500 complex values to be stored.[7] (For comparison, a terabyte of digital information stores only 243 discrete on/off values.) Nielsen and Chuang point out that "Trying to store all these complex numbers would not be possible on any conceivable classical computer."[7]

I don't think making normal CPU's bigger is really an option. They require more power, create more heat, and are much less efficient. They would also cost more because there would be fewer cores per wafer.

I may be completely wrong though, in which case I'm sure someone will correct me.

I'm no expert, but I have been paying attention. (I hope!) The idea with Quantum Computers is that they would be able to solve certain problems much faster, since they would work on all possibilities at the same time instead of one after another.

When we (humans) started exploring organic chemistry there were unanticipated negative consequences. As described in the article, will the same be true for quantum computing?

Watching "Deadliest Catch" and seeing us (humans) selectively eliminiating all the large crabs and letting the smaller crabs survive to reproduce, would suggest we are incapable of learning from our errors of the past. Will our hubris get us into trouble with quantum computing and the associated advancements?

Only thing that's practically different from current computing and quantum computing is a bit can be in more than one state. I can't fathom what kind of terrible fate will befall us because of it.

Quantum computing is not yet a reality. I will believe it when I see it. It's kind of like the parallel computing myth that so many believe it, but hasn't yet come to fruition. I know this article is not about AI, but it's another myth that is popular as well. True artificial intelligence will require a computer that can write new software for itself on the fly. Anything less is nothing more than a computer with clever algorithms. I've been watching these computer fantasizers at work now for a couple of decades, and the myth-spinning just never stops. Reminds me of the much-ballyhooed "thin client" promoted by Larry Ellison of Oracle. He predicted back in the 90's, I believe, that within some number of years that PC's would all be replaced by thin clients running from central servers. Well, where are they? I'm attending college for a computer science degree, and while I see quite a few small devices being used by individuals, our classrooms are filled with supposedly extinct and useless PCs! My point is that I am not impressed by articles such as this that predict the myth of imminent "computer heaven" if only we have "the next big thing" which "will revolutionize the world". I'm tired of hearing it.

Some help from a non-expert:Right now quantum computing is not at the stage where we have a real computer, but we *can* do (very) simple calculations (eg. factor the integer 15). The thing is, while we didn't know what would be possible when we invented the vacuum tube, and then the transistor, we have a much better idea of what *may* be possible with quantum bits.So yes, quantum computing and AI are "myths" because we haven't achieved them - yet. Just like men on mars is a "myth".(Also, rewriting your own software is trivial, there's much more to it than that. On the other hand, no one's quite proved that human intelligence is not just "clever algorithms")

Keep in mind that a quantum computer is not just a 'more powerful' classical computer, it literally operates under a different model - making different things possible. This also doesn't mean that it will be superior to classical computers in even most ways.

I don't think making normal CPU's bigger is really an option. They require more power, create more heat, and are much less efficient. They would also cost more because there would be fewer cores per wafer.

I may be completely wrong though, in which case I'm sure someone will correct me.

I heard that current implementations of quantum computer requires phenomenal amount of power control decoherence for even few seconds.

A major application of quantum computing is its extremely fast Fourier transform, O(n^2) versus O(n2^n) on a contemporary machine. This famously turns the factoring of large numbers from a Hard Problem into a trivial calculation that doesn't leave enough time to take a sip of coffee via Shor's Algorithm.

The Fourier transform is the most impressive known speedup, but there are other benefits as well. Quantum computers in general benefit from being fundamentally parallel in their operation. Their calculation power increases exponentially with an increasing number of qubits available. Imagine a 64-bit computer being 2^56 times more powerful than an 8 bit machine because it can simultaneously investigate a subset of the solution space that is 2^56 times larger, roughly speaking.

Has anyone tried building a quantum simulator out of traditional materials? So for example instead of having a single transistor makeup the "bit" you might have 32 transistors (or whatever) wired together in such a way as to simulate a single quantum "bit".

When we (humans) started exploring organic chemistry there were unanticipated negative consequences. As described in the article, will the same be true for quantum computing?

Only thing that's practically different from current computing and quantum computing is a bit can be in more than one state. I can't fathom what kind of terrible fate will befall us because of it.

Sorry - should have been clearer that the concern is more to do with the examples of the application of quantum computing, rather than quantum computing in unto itself.

The article states "This is the shining promise of a future with quantum computers. It is a future that is being brought about by the great experimental physicists of our time, but, it is also a future that will be owned by biologists and chemists."

While I read the examples of materials design using quantum computing, this seems like a clever idea. However, I'm just wondering if we're clever enough to define the requirements for new materials correctly. From the article, with the bits that were possibly overlooked in parentheses: "Need a strong plastic that biodegrades into harmless bi-products?" (to mammals, but is highly toxic to nitrogen fixing microbes) or "Harder materials will increase the longevity of gadgets" (but are extremely energy intensive to recycle). Inventions like carbon nanotubes can/will be used for amazing things, however this doesn't mean they shouldn't be considered toxic.

My point about the crabs is that we demonstrably don't seem to learn from history. While discoveries such as x-rays and organic chemistry have yielded some great things, lots of people died early while we eventually took the time to figure out what was really going on. Does anyone have any examples of research and development processes that are so comprehensive that a bit of caution isn't called for? Especially when these guys are the guiding lights? http://arstechnica.com/staff/2012/10/ed ... t-science/

Beyond the basics, thank you for writing such an impassioned and enthusiastic article. It's really nice to hear (read?) the passion that pushes scientists forward to discover newer (cooler?) things and apply them to our everyday lives.

When we (humans) started exploring organic chemistry there were unanticipated negative consequences. As described in the article, will the same be true for quantum computing?

Only thing that's practically different from current computing and quantum computing is a bit can be in more than one state. I can't fathom what kind of terrible fate will befall us because of it.

Sorry - should have been clearer that the concern is more to do with the examples of the application of quantum computing, rather than quantum computing in unto itself.

The article states "This is the shining promise of a future with quantum computers. It is a future that is being brought about by the great experimental physicists of our time, but, it is also a future that will be owned by biologists and chemists."

While I read the examples of materials design using quantum computing, this seems like a clever idea. However, I'm just wondering if we're clever enough to define the requirements for new materials correctly. From the article, with the bits that were possibly overlooked in parentheses: "Need a strong plastic that biodegrades into harmless bi-products?" (to mammals, but is highly toxic to nitrogen fixing microbes) or "Harder materials will increase the longevity of gadgets" (but are extremely energy intensive to recycle). Inventions like carbon nanotubes can/will be used for amazing things, however this doesn't mean they shouldn't be considered toxic.

My point about the crabs is that we demonstrably don't seem to learn from history. While discoveries such as x-rays and organic chemistry have yielded some great things, lots of people died early while we eventually took the time to figure out what was really going on. Does anyone have any examples of research and development processes that are so comprehensive that a bit of caution isn't called for? Especially when these guys are the guiding lights? http://arstechnica.com/staff/2012/10/ed ... t-science/

As I understand from D-Wave project, they are using material that are already commonly used in computering and aeronautics. Only thing they are doing out of ordinary is that they have to pump supercooled gas.

Otherwise, it's the same risk as any other computing technology; eating through our copper and gold reserves as well as toxin from manufactuering process, wastage etc etc etc.

AS a Cambridge University computer science graduate with some studies in chemistry, physics and electronics (albeit, very little specialist training in quantum mechanics); I never heard anything in all of my training or in all of my reading of popular literature that convinced me that "quantum computers" will be anything fundamentally better than what we have now. On the contrary, I am convinced that the fundamental limitations of computer science will still apply (after all, applying different general-purpose calculation hardware doesn't fundamentally change the nature of the calculation or of mathematics itself!)

With quantum mechanics, we might find some interesting probabilistic algorithms, analogous to what could be achieved on the old analogue computer technology (we might simulate the quantum mechanics of the system we want to study). We might find that quantum mechanics takes us to the "next level" beyond the CMOS end-point. But between the probabilistic or ultra-sensitive nature of quantum mechanics, and the problems of maintaining quantum "coherence" and then breaking it; I think we'll find that we are replacing one set of technical problems with another — and in the end, like-for-like, only gaining a proportional increase in computation speed — perhaps a very significant proportional increase, but nonetheless, when you start applying a quantum computer (which is limited by physical qubit width) to a problems of unlimited size (we're talking about "big-O" complexity here); you're going to require a "divide and conquer" algorithmic approach and will encounter the fundamental limitations that are common to all Turing machines; even if your quantum computer is perfect! I might say,"Show me a quantum computer that can factorise an n-bit number, and I'll use a similar machine to generate a number you can't factorise on your machine in time less than the age of the universe."Until we solve the fundamental issue of how to prime factorise, there's no machine that will wave this magic wand and do it all for us.

Dracorat wrote:

Why do I get flashbacks to the days of computers running by vacuum tubes and the articles of the time then?"Want a problem solved? The magic of the computer can do it for you!"For better or worse.

— Similarly, as illustrated by "Dracorat", understanding electronics did not fundamentally change the nature of basic arithmetic. It did enable the development & implementation of some methods that were previously impractical... But maths is still the same. It's basic arithmetic we need to understand if we are to do a better job of basic arithmetic.

Rumours of "quantum computing" devices have been sloshing around in the popular media for almost 30 years now. This is becoming classic vapour-ware. The build-up to this has been rather like the build-up to (fission-based) nuclear power in the early part of the 20th Century... After being anticipated for decades, fission power arrived, but its disadvantages were far greater than anticipated. For all we know at this stage, quantum computing might fall into the same trap. I'm a little more optimistic than this though... I think we'll all get a large proportional boost in desktop computing speed when this technology finally matures...

OK, so am I right in thinking that the main point of quantum computing is not "they're super fast" but that they might turn "NP-complete", or maybe even "NP-hard" problems into "P" problems.

I'm no expert on computing theory or quantum computers, so in layman's terms this would mean a quantum computer could solve the "travelling salesman problem" or play chess without having to do a slow calculation going through all the possible moves and comparing them.

For the even layer layman, a quantum computer will DO ALL THE THINGS! whereas a conventional computer has to "do ALL the things..."

I guess the hard part would be figuring out how to write a quantum algorithm. I imagine it will be very different to an algorithm designed to run on a turing-machine. The fundamental rule of "Garbage-in, garbage-out" won't be revoked by a quantum computer.

Let me answer several points here at once. No, this article does not go into the details of what a quantum computer is, or how it works: it wasn't the point of the article.

To briefly summarize: quantum computers are not magical, and cannot solve NP-hard problems efficiently (at least, as far as we know). But, it has been mathematically proven that a computer that can make use of the quantum properties of superposition, entanglement, and coherence, can solve certain problems much faster than a classical computer.

One of the commenters above gave the example of factorization, but that is the least interesting. The big thing is that a quantum computer can solve the equations of quantum mechanics efficiently, while a classical computer cannot. If we should manage to make a useable quantum computer then it will no longer be necessary to use the approximations that are currently used in quantum chemistry to try and determine molecular properties.

It may be possible to exactly calculate the properties of molecules, including polymers and their interactions with each other. Once we are on this track, suddenly, it becomes possible to rationally design materials with desirable properties, and then use the same calculation to investigate if the product has any undesirable properties.

My personal view is that quantum computers will be common in science labs before I retire.

"...who hasn’t watched in horror as the glass in their cellphone cracks after being dropped..."— I already have a solution for this! £45 Nokia smart-phone: plastic screen.

The first half of the article is fine but the second half is silly. Any time someone tells me their invention is going to generally do away with the need for human creativity, I get VERY sceptical...

The way I understand things it's more like what happened to building design when CAD took off. You got much more varied designs and ones that could be tweaked to be much more environment friendly/disaster proof/etc. coming out.

The architects themselves didn't get overthrown by CAD, they embraced it and moved ahead by leaps and bounds in their field.

When we (humans) started exploring organic chemistry there were unanticipated negative consequences. As described in the article, will the same be true for quantum computing?

Watching "Deadliest Catch" and seeing us (humans) selectively eliminiating all the large crabs and letting the smaller crabs survive to reproduce, would suggest we are incapable of learning from our errors of the past. Will our hubris get us into trouble with quantum computing and the associated advancements?

Er, the idea of having a minimum size for the crabs caught is largely to insure that they've reproduced quite a bit before being taken. Since each crab has thousands of eggs each season, there's no winnowing of the "large crab gene pool". The crabs are heavily regulated, largely to keep a healthy, thriving population.

I'm sorry this non-issue has caused you distress. ;-)

As to quantum computing, I'm not worried about it in particular, but if the Singularity comes to pass there will be highly unpredictable, and perhaps disastrous, consequences.